This dissertation is about improving performance of projects delivering complex systems. Examples of such systems are ships, infrastructure systems and process plants. Mostly these systems are one of a kind, so called ‘one-offs’ and are the ‘product’ of one or more coherent projects each executed by a consortium of enterprises. The lifecycle of these systems is characterized by a sequence of lifecycle stages (in headlines specification, creation and usage) and requires involvement of different parties with different interests and competences, e.g. the client, (sub) contractors, end users and stakeholders and disciplines like construction, electrical, mechanical and information technology. In actual practice many of these kinds of projects exceed the planned budget and time and do not meet the quality and needs expected by the client, end users and/or stakeholders. This dissertation considers this problem from an overall perspective, and not from the perspective of only e.g. the client or contractor. In this dissertation three issues have been identified concerning today’s creation of systems: •Imperfections in the creation process of both systems and the project teams that create the system, •Lack of reflection, •Lack of semantic ability. The objective of this dissertation is to provide a framework in which the backgrounds of these three issues are expressed and offer a way to overcome these issues. The framework can be utilized by enterprises to improve interoperability and symbiosis in the field of Systems Engineering enabling them to improve performance of projects in all lifecycle stages of a system. The framework addresses interoperability barriers and integrates Systems Engineering principles, organization science, system science, complexity science and cognitive science. The framework has been visualized by means of six symmetrically connected tetrahedrons, supported by an ontology. Additional terms of reference has been drawn up for the purpose of implementation of the framework. A prototype of a collaboration tool based on a specific semantic WEB technology as published in several papers by the author, supporting the framework, was part of the work done for this dissertation. The framework is based on years of experiences of author with complex projects and knowledge as captured in ISO standards and fundamental theories.